Holographic recording has received attention as one of high-speed large-capacity storage techniques.
In this holographic recording, the refractive index of a recording layer material in a recording layer of a holographic recording medium is changed according to interference fringes of an object beam and a reference beam to thereby form a hologram.
The hologram formed in the recording layer of the holographic recording medium according to the interference fringes of the object beam and the reference beam as mentioned above cannot be easily erased in contrast to the case for a magnetic recording medium.
Therefore, conventionally, when a holographic recording medium is, for example, discarded, the holographic recording medium is irradiated with a high energy erasing beam or is physically destroyed. Since no other means can be employed, problems exist that data erasing is complicated and the processing cost is high.